“One of our major goals in putting the paper out there was to encourage other people who study migratory animals that may have moved from Japan to look for things like this,” said Madigan.

KCBS’ Jeffrey Schaub Reports:

The tuna were caught by sport fishermen near San Diego and are not the type sold in U.S. markets.

This marks the first time that a huge migrating fish has carried radioactivity such a distance. The level of radiation was 10 times higher than the amount measured in previous years, but still far below safe-to-eat limits.

But Chris Harrold, Director of Conservation Research at Monterey Bay Aquarium, said there is still an important message in the findings.

“We now know that something that happened in Japan, we’re seeing the impacts here in California,” said Harrold. “There were probably lots of other events, both natural and man-caused, that are transmitted in other parts of the world in ways that we don’t know.”

Previously, smaller fish had carried elevated levels of radiation following the devastating earthquake and tsunami in Japan last March, which badly damaged nuclear reactors in the country.